The vector illustration "Mandatory construction related icon set two" from Barry Barnes is available on Fotolia under a Royalty Free license from 1 credit (Credit from $0.74).

Available in AI/EPS and JPEG formats, this vector file may be downloaded for all kinds of professional uses. The V and XV files are delivered in AI/EPS. To modify this file, vector editing software such as Adobe Illustrator, Freehand, or CorelDRAW is required. JPEG files are available in different resolutions (up to 3,775 x 3,974 pixels in 300 DPI).